MADRID (Reuters) - The Bank of Spain has asked for detailed information after recent disruptions to the country's payments network, a source close to the central bank said.

Spain's largest payments platform Redsys crashed last weekend and again on Nov. 23, ahead of Black Friday, which is one of the busiest periods of commercial activity.

The more than 35-year-old online Spanish platform acts as an intermediary between banks, shops and buyers to ensure the security of transactions. It says it handles more than 45 million payments per month.

The source said the central bank has not opened a formal case into Redsys, which is owned by Spanish banks including Santander, BBVA and Caixabank and handles their electronic payments business.

Customers complained on social media about failed ATM withdrawals and credit card payments on Nov. 18. Redsys responded by saying disruptions had been resolved and were due to internal communication lines, ruling out any external attack.

Redsys suffered further disruptions on Nov. 23.

"A technical incident has occurred which has caused temporary instability in the system responsible for processing payment transactions. The service has been fully restored," the company said.

The central bank is looking into both incidents, which come as European Central Bank (ECB) data shows cash payments in Spain fell by 18% between 2019 and 2022, a figure only surpassed in the euro zone by Cyprus, where transactions fell 23%.

Redsys competes with another payment provider in Spain, which belongs to Cecabank and holds a market share of about 15%.

(Reporting by Jesús Aguado; Additional reporting by Emma Pinedo; Editing by Inti Landauro and Alexander Smith)